Apparatus, method and kit for aligning an integrated circuit to a test socket

ABSTRACT

An apparatus, method and kit is provided for aligning small, closely spaced leads of an integrated circuit to small, closely spaced test conductors within a test apparatus. The leads can be arranged in various ways, and can extend from dissimilar types of integrated circuit packages. Likewise, the test conductors can be configured from a test socket possibly within a test head. The integrated circuit or DUT is forwarded toward the test conductors by a handler. The kit is used to secure the DUT and align the leads with the test conductors. Alignment can be achieved in either two or three dimensions. According to one embodiment, the kit includes a test socket unique to the DUT having at least one pin, and preferably two pins, extending from the test socket through an insert, also provided with the kit. T he insert retains the DUT and the opening within the insert extends over the pin to effectuate two-dimensional alignment. A spacer may also be provided with the kit as an alternative embodiment. The spacer can be affixed to the test socket outside the test conductors. The spacer operates similar to a shim and is designed to abut between the test socket and the insert. A change in the thickness of the spacer will modify the spacer thickness will provide alignment in a third dimension so that optimal electrical contact is achieved between leads and test conductors.

RELATED APPLICATION

This application is related to a co-pending U.S. Patent Application toOrso and Chhor entitled "Apparatus, Method and Kit for AdjustingIntegrated Circuit Lead Deflection Upon a Test Socket Conductor" whichis incorporated as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to automated handling of an integrated circuitduring test of that integrated circuit and, more particularly, to anapparatus, kit and method used to transversely align leads extendingfrom the integrated circuit to test conductors extending from a testsocket.

2. Description of the Related Art

The sequence of steps used in forming an integrated circuit oftenculminates in an assembly or packaging operation. Assembly involveshermetically sealing the integrated circuit or die inside a carrier, orwithin an encapsulant injected about the die. A result of the assemblyoperation is to protect the integrated circuit against contaminantsarising from the environment into which it is placed. Only leads extendfrom the packaged product into the environment. The leads areelectrically connected to bond pads generally arranged around theperiphery of the integrated circuit. Depending on the size or complexityof the integrated circuit, the leads can take on numerous configurationsand/or arrangements, and therefore the packaged product can beclassified as a dual-in-line package (DIP), a quad flat package (QFP), aball-grid array (BGA), a single-level integrated module (SLIM), forexample.

Before the packaged product can be used on, for example, a printedcircuit board (PCB), it is necessary that the circuit be tested afterthe assembly operation and before its use in the field. For example,placing the integrated circuit inside the carrier or injectingencapsulates about the circuit may damage or skew the operatingparameters of the integrated circuit. As such, mechanisms have beenemployed to rapidly test packaged integrated circuit prior to shippingthose circuits to a customer.

A common test mechanism involves placing a test head against theintegrated circuit leads. The test head contains high speed circuitswhich generate test signals and measure the result of those signals uponthe integrated circuit. Thus, a test head may employ multiple signalgenerators as well as multiple voltage and/or current meters. The testhead may also include a test socket. The test socket is one that isunique to the integrated circuit being tested, often referred to as the"device under test" or DUT. A plurality of test conductors extend fromthe test socket in registry with leads extending from the packagedproduct or DUT. Depending on the arrangement of those leads, the testsocket can be configured in numerous ways with associated testconductors arranged unique to those leads.

A handler is used to place the DUT such that its leads extend againstthe test socket conductors. Most modern day handlers use apick-and-place technique, whereby DUTs are drawn in succession from aninput position to a holding device. The holding device is then movedtoward the test socket with the DUT securely fixed within the holdingdevice. After contact between the leads and the test conductors havebeen accomplished, and the test signal stimuli sent and resultsrecorded, the holding device and DUT are then drawn away from the testsocket. Based on the outcome of the test relative to the integratedcircuit specification, the pick-and-place mechanism within the handlerthereafter places the DUT in the appropriate bin position.

A primary function of the handler is to repeat movement of the holdingdevice and DUT in rapid succession from one position to another. Thisentails repeatably placing leads of the DUT in accurate alignment withtest conductors emanating from a test socket. At best, this is difficultto achieve. For example, many modern QFPs may have a hundred or moreleads extending from a periphery less than three centimeters per side.Moreover, the pitch distance between leads may be less than 50 mils. Anymisalignment between those leads and the test conductors may causeimproper electrical contact or, in the worst case scenario, bending ofthe leads or test conductors. Even in instances where the DUT isleadless, or utilizes solder balls rather than leads, misalignment ofthose leadless receptors and the test conductors might prevent contactbetween the receptors and test conductors and/or damage the elongatedtest conductors which extend from the test socket. Misalignment maycause the test results to indicate an open circuit or failure when, infact, the DUT is not a failure. The stimulus applied by a misalignedtest conductor may contact a neighboring lead and damage circuitsconnected to that lead.

Conventional mechanisms for aligning leads to test conductors primarilyfocus upon the test head and the handler. That is, many alignmentmechanisms rely on the distance between the test socket and a test headcoupler upon the test head remaining fixed over time. There is generallyanother coupler upon the handler arranged a pre-defined distance fromthe point at which the DUT is delivered from the handler toward the testhead. That distance is supposed to be the same distance as that whichseparate the test socket and the test head coupler. In this manner, thecoupler upon the test head and the coupler upon the handler connect withone another and, hopefully, the test socket will align with the DUT.However, after inserting multiple DUTs in succession against the testsocket, the delivery mechanism used by the handler will begin to wear.The extent of that wear will degrade or skew the delivery point from itsinitial delivery position. This may result in misalignment of the DUTleads relative to the test conductors. It would therefore be beneficialto derive an alignment mechanism which can maintain the alignment afterrepeated use, and can also expeditiously establish alignment of thefirst DUT to the test socket at the moment after which the test head andhandler is retrofitted with a test kit. Thus, the desired alignmentmechanism would prove advantageous if it can be obtained as a kit,comprising the test socket and the DUT holding mechanism. That kit wouldbe particularly useful if it contains a mechanism not only to ensuretransverse alignment of the leads to the test conductors, but alsomaintains a proper depth by which a respective lead is thrust upon acorresponding test conductor. Maintaining alignment in three dimensionfor dissimilar lead arrangements of numerously different packagedproducts would serve to minimize damage to the DUT, damage to the testsocket, and waste of what would otherwise be electrically acceptableDUTs.

SUMMARY OF THE INVENTION

The problems outlined above are in large part solved by an improvedapparatus, kit and method for delivering a DUT in alignment with a testsocket. The delivery apparatus includes any apparatus which is calledupon to repeatedly apply closely spaced items against correspondingclosely spaced items, preferably for use in testing those items. Thus,the intended application extends beyond the testing of integratedcircuits and is applicable to testing a generic device (i.e., DUT). Thedelivery apparatus may utilize an existing handler suitably used in thetesting of an integrated circuit. A retrofit is performed on the devicewhich retains the DUT in position against the test socket. The retainingdevice (henceforth referred to as an "insert") includes at least oneopening or alignment hole. According to a preferred embodiment, thealignment hole extends over a pin arranged on an outer surface of thetest socket. According to a more preferred embodiment, the insertincludes at least two alignment holes spaced from each other. At leasttwo pins extend from the test socket and through the alignment holeswhenever the insert, and DUT fixed within the insert, is receivedagainst the test socket.

A spacer may be used in addition to the alignment pins extending fromthe test socket. While a spacer is not necessary in all instances, itcan be used in conjunction with the alignment pin to provide additionalalignment in a third dimension. The spacer may be secured against thetest socket in a region spaced laterally away from, or outside of, thetest conductors. The spacer is preferably a rigid material such asmetal. According to one suitable form, the spacer may be a contiguoussheet secured to a contiguous planar surface of the test socket. Thecontiguous spacer is designed to receive a planar surface of the insertin an area outside of the DUT. Thus, the spacer serves as a "shim" toestablish the extent by which the DUT (and particularly the leads) movesin the direction of the test socket, based on the thickness of thespacer. According to an alternative form, the spacer may comprise anextendable pin, or possibly a screw, protruding from an isolated regionof the spacer against the insert outside the area of the DUT wheneverthe insert is drawn against the test socket or, in this case, againstthe spacer. According to yet a further form, the spacer may comprise acap securely fixed to the end of an adjustable-length or fixed-lengthpin. In the latter instance, the cap can be of variable thickness toaccount for a fixed-length pin. In each example, the spacer is designedto "space" the insert away from the test socket. By modifying thethickness of the spacer, regardless of the form in which it takes, thespacer can adjust the amount by which leads of the DUT extend againstrespective test conductors.

While the spacer ensures optimal movement of the insert and thereforethe DUT leads, the alignment pins and alignment holes ensure alignmentwithin a plane approximately perpendicular to the direction at which theDUT extends towards the test socket. The alignment holes may be slightlytapered near the surface of the insert. This allows the alignment pinsto be channeled into the alignment hole and therefore to self-alignleads to test conductors each time the DUT-embodied insert is directedagainst the test socket.

The insert and test socket can be acquired as a kit specific to aparticular integrated circuit. The insert can be machined based on theoutline of the DUT, with alignment holes in registry with pins machinedupon a test socket having test conductors unique to the DUT leadconfiguration. Additionally, the kit may include a chuck which extendsagainst a surface of the insert opposite the surface containing the DUT.A benefit in purchasing the kit is that the present alignment mechanismcan be used with any integrated circuit lead configuration by simplychoosing a kit specific to the integrated circuit being tested.Moreover, the kit can be used with any handler which includes an armthat draws a DUT against a test socket. Of importance is that thealignment mechanism (pins, holes, and/or spacer) is arranged as close tothe DUT as possible. Thus, instead of relying upon the test socket tomaintain alignment with the test head coupler and the delivery pointmaintaining alignment with the handler coupler (or docking plate) thepresent alignment mechanism operates close to or directly upon theholding mechanisms (test socket and insert) at which precisionelectrical mating of test conductors to leads is needed. Conventionaltechniques of aligning the docking plate on the handler to a chassis ofthe test head simply proves unworkable as an exclusive alignmenttechnique since wear on the delivery mechanism compromises the deliverypoint of the pick-and-place handler.

The spacer can be machined to any desired thickness depending upon theamount of the deflection and/or contact needed between the leads and thetest conductors. By changing that thickness, electrical connectionbetween the leads and test conductors can be optimized. Electricalconnectivity can be repeatedly assured using a single spacer upon thetest socket rather than on possibly multiple inserts drawn to the singletest socket. Using a single spacer or shim to account for variances inthe insert-to-socket spacing proves beneficial not only in costs butalso by virtue of its reliable repeatability among multiple inserts andDUTs.

Broadly speaking, the present invention concerns an apparatus foraligning an integrated circuit to a test socket. The apparatus mayinclude a test system, and the test system may include a test head and ahandler which delivers a DUT to the test head. Alternatively, theapparatus includes a test socket and an insert. The test socket includesat least one pin extending therefrom. That pin is placed within anopening within the insert whenever the insert is brought near the testsocket. When the pin is channeled into the opening, the insert is movedalong a plane perpendicular to an axial dimension directly separatingthe insert and the test socket. Channeling the pin into the openingtherefore moves the insert in a transverse direction such that leads ofa DUT fixed within the insert move accordingly. The pin-and-openingarrangement is used to self-align leads upon the DUT with testconductors upon the test socket each time the pin is mated within theopening.

The delivery mechanism may include a kit, according to one embodiment.The kit is used to align a lead of an integrated circuit to a testconductor of a test socket. The kit includes a test socket and aninsert. A test socket surface of the test socket includes a pin and atest conductor spaced a first distance apart. The test conductor is oneof numerous test conductors extending from the test socket. The insertincludes an insert surface configured to receive the integrated circuithaving multiple leads. The insert surface also includes an openingspaced from a particular lead by a second spaced distance. Preferably,the first spaced distance is equal to the second spaced distance suchthat the opening receives the pin concurrent with the test conductorcontacting the lead of interest. There is preferably another pin, andanother test conductor extending a known distance from each other. Thatdistance is commensurate with the spacing between an opening receivableby the pin and another lead. The kit can be purchased with or separatefrom the test system. If purchased separate, the kit can be unique to aparticular DUT and can repeatedly self-align any unique arrangement ofleads on the DUT to test conductors on the test socket by merely placingpins on the singular test socket successively into openings in aplurality of inserts dimensioned to receive respective DUTs.

A method may also be used to align a lead of an integrated circuit to atest conductor of a test socket. The method includes placing theintegrated circuit into an insert and moving the insert toward the testsocket. The insert may thereafter continue moving while it is beinglaterally shifted relative to and along a plane parallel to the testsocket when bringing the lead in alignment with the respective testconductor.

According to another embodiment, a spacer may be included with theapparatus and/or kit. The spacer is used to adjust compression of thelead against the test conductor. Thus, the kit and/or apparatus includesa spacer of adjustable thickness interposed between the test socket andthe insert which retains the integrated circuit leads. The spacer cantake on numerous configurations, including a contiguous, planar element,a pin which can adjustably extend from the test socket, or a variablethickness cap placed over a pin of fixed length, or possibly otherconfigurations as well.

A method can be used to adjust compression of a lead against the testconductor. By continuing to move the insert, a surface of the insertoutside the integrated circuit will abut against the spacer concurrentwith the lead compressing against the test conductor. All of the variousforms and embodiments which include an alignment pin upon a test socket,an alignment opening upon an insert, and a spacer therebetween, providethree-dimensional alignment of a relatively small component to anotherrelatively small component each time those components are brought inclose proximity to each other. The components can, according to oneembodiment, be applicable to integrated circuits or generally to themating of any relatively small, fine-pitch components which frictionallyand electrically engage with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to theaccompanying drawings in which:

FIG. 1 is a perspective, plan view of a handler coupled to a test head,wherein the handler includes a mechanism for moving an insert containingan integrated circuit and placing leads of the integrated circuitagainst a test socket within the test head;

FIG. 2 is a cross-sectional view of the integrated circuit leadsmis-aligned relative to test conductors emanating from the test socket;

FIG. 3 is an exploded view of a chuck which extends the insert throughan opening within the handler in transverse alignment with the testsocket by placing openings within the insert and chuck about pinsextending from the test socket;

FIG. 4 is a cross-sectional view along plane 4 of FIG. 3, illustratingthe chuck, insert and integrated circuit fully extended against the testsocket which, according to one embodiment, includes a spacer of variablethickness extending from the test socket toward the insert;

FIGS. 5a, 5b and 5c are cross-sectional views along plane 5 of FIG. 4,illustrating various forms usable as the spacer and also illustratingthe alignment pin of the test socket extending into a tapered openingwithin the insert for laterally moving the insert, and integratedcircuit fixed within the insert, to a position whereby the integratedcircuit leads are aligned with conductors of the test socket and theleads deflect upon the test conductors an amount adjusted by the spacerthickness; and

FIG. 6 is a flow diagram of a method used to align the integratedcircuit leads with the test socket conductors.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will herein be described in detail. Itshould be understood, however, that the drawings and detaileddescription thereto are not intended to limit the invention to theparticular form disclosed, but on the contrary, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope of the present invention as defined by the appendedclaims.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Turning now to the drawings, FIG. 1 illustrates a test system 10. Testsystem 10 includes a test head 12 and a pick-and-place handler 14. Testhead 12 may contain circuitry which generates test signals andmeasurement tools which quantify responses created by those signals upona DUT. Accordingly, test head 12 includes a test socket 16 having aplurality of test conductors 18 arranged on a bottom surface of testsocket 16. Test conductors 18 represent the distal ends of conductorswhich deliver test signals to the DUT and gather responses from the DUT.Test conductors 18 are arranged upon one surface of test socket 16.According to the embodiment shown, test conductors extend downwardtoward handler 14.

Handler 14 includes any mechanism which, through automation, presentsDUTs in rapid succession to the test conductors 18 of test head 16.According to one embodiment, handler 14 involves a robotic arm 20 whichreceives a DUT 22, possibly contained within a tray 24. Arm 20 may thenserve to place the DUT at an input position of a respective insert 26.As shown, numerous inserts 26 can be placed about a carousel 28 which isarranged in a heated or cooled chamber 30.

The heated (or cooled) DUT 22 can then be drawn upward within itsrespective insert 26 by a chuck 32. The DUT 22 retained within insert 26is then secured against the underside of test socket 16 and, moreparticularly, leads of DUT 22 are secured against respective conductors18 of test socket 16. Once circuitry within test head 12, or distalcircuitry within test device 34, forwards and receives test signals andresponses, the test operation has concluded and the DUT-embodied insertis drawn away from test socket 16 by lowering chuck 32. A robotic armcan then be used to place the tested DUT within a particular tray 36 or38 depending on the results of that test. For example, tray 36 maycontain DUTs which fail the parametric and functional tests performed bytest head 12 and/or test device 34.

FIG. 2 illustrates a problem which might occur absent the transversealignment features (pins and openings) described herein below.Specifically, FIG. 2 depicts an insert 26 which may be configured tocontain a DUT 22. Leads are arranged either about the periphery of theDUT or as an array across one surface of the DUT. Leads 40 are shownslightly skewed 42 from test conductors 18 of test socket 16. The skewis shown as translateral or transverse, or any other term used toindicate that leads 40 are misaligned from conductors 18 relative to aplane parallel to the plane formed by the ends of leads 40 and the endsof conductors 18. In other words, misalignment is along the planeperpendicular to an axis which directly separates the test socket andthe delivery mechanism. Thus, as the delivery mechanism forwards theDUT, misalignment is shown perpendicular to that forward movement.

FIG. 3 is an exploded view of various components used to align an insertand therefore the DUT to test conductors upon the test socket.Specifically, a test head 12 is shown having an underside surface whichcan accommodate a test socket 16. The test socket can be secured to theunderside surface by various means such as, for example, screws,latches, etc. According to another embodiment, test socket 16 is securedto the underside surface by a retainer 48. Retainer 48 may includescrews extending from the upper surface of retainer 48 and into theunderside surface of test head 12. The lower surface of retainer 48includes a conical opening 50 and an insert pin 52. By applying tensionto the screws (not shown) retainer 48 secures test socket 16 to testhead 12 using, for example, frictional engagement according to onesuitable mounting technique.

Retainer 48 may be aligned in various ways. For example, insert pin 52extending from retainer 48 may be first placed within opening 54 ofdocking plate 56. Once placed in position, and test conductors 18 oftest socket 16 are properly aligned, test socket 16 and retainer 48 aredrawn from docking plate 56 and secured in the aligned position againstthe underside surface of test head 12. As such, the test head 12 servesto retain test socket 16 and retainer 48 in a secured and presumablyaligned position.

Docking plate 56 is deemed any rigid material which is secured to theupper surface of handler 14 (shown in FIG. 1). Docking plate 56 includesan opening 58 through which the conical opening 50 extends whenever testhead 12 is secured or "docked" onto handler 14 and, more particularly,docking plate 56. Also associated with docking plate 56 is a pair ofopenings 60 which serve to secure pins 62 extending from the undersidesurface of test head 12. The arrangement of pins 62 and openings 60 forma coupling mechanism whenever the test head is placed on top of thehandler. The pins and openings serve to secure the test head to thehandler in the docked position. Of course, there may be numerous othercoupling mechanisms used to secure the test head to the handler.

Aligning the test socket 16 to test head 12, and securing test head 12to docking plate 56 of handler 14 does not ensure optimal alignment ofthe DUT leads to test conductors 18. In addition to the dockingarrangement, a more precise alignment of the exact objects being alignedis needed. Thus, one of the present advantages is at least one pin 70,and preferably at least two pins 70, are configured on the undersidesurface of test socket 16. As will be described below, pins 70 arechanneled into openings 80 whenever insert 26 is drawn against testsocket 16. It is known that test socket 16 comprises primarily a printedcircuit board having numerous circuits arranged thereon. Extending fromthe printed circuit board are distal ends of test conductors 18 whichface downward in the example shown. Test conductors 18 therefore extendfrom a planar underside surface of test socket 16 in a region laterallyspaced from pin 70. In other words, pin 70 extends from test socket 16outside of the regions occupied by test conductors 18. Moreover, pins 70extend downward through at least an upper portion of the conical opening50 whenever the test head is docked to the handler. FIG. 3 illustratesin more detail chuck 32 and a vertically moveable arm 72 arranged on theunderside surface of chuck 32. Arm 72 serves to drive upward chuck 32through docking plate 56 and partially through conical opening 50. Chuck32 includes a set of pins 74 which mate with openings 76 in insert 26.Pins 74 secure insert 26 against lateral or perpendicular movementrelative to the direction at which arm 72 drives insert 26 against theunderside surface of test socket 16 and through openings 50 and 58.Accordingly, the robotic pick-and-place handler (shown in FIG. 1) servesto repeatably move a DUT-embodied insert 26 through opening 58 at theupper surface of handler 14, and also through the retainer 48 such thatleads of the DUT extend upward in frictional engagement with testconductors 18.

FIG. 4 illustrates a cross-sectional view along plane 4--4 of FIG. 3.Specifically, FIG. 4 depicts a DUT 22 embodied within insert 26 anddriven to its optimal height proximate to the underside surface of testsocket 16. According to one embodiment, DUT 22 can be configured as aQFP with leads 40 extending about the periphery of DUT 22. Leads 40 areshown aligned with test conductors 18 along a plane parallel to theunderside surface of test socket or the upper, inverted surface of DUT22. In a peripheral-lead arrangement, a portion of insert 26 extendsupward against an underside of leads 40 to provide support when theleads extend against the test conductors. Alignment of leads 40 to testconductors 18 is achieved by the mating of pins 70 within openings 80.

According to the example shown, pins 70 and openings 80 providehorizontal alignment. In addition to horizontal alignment, a spacer 82may be used to provide vertical alignment. Of course, it is understoodthat the arrangement indicates vertical thrusts of arm 72 and chuck 32;however, it may also be assumed that chuck 32 can be driven in thehorizontal direction, whereby pins 70 and openings 80 take on a vertical(rather than a horizontal) alignment function. Regardless of thearrangement of the delivery mechanism, the combination of pins 70,openings 80 and spacer 82 provide three-dimensional alignment of leads40 to test conductors 18. FIGS. 5a-5c illustrate numerous configurationsof leads upon a DUT, and a spacer which provides vertical stop of leadsagainst test conductors.

FIG. 5a illustrates a detailed view along area 5 of FIG. 4, except thatFIG. 5a indicates a slight space between insert 26 (or leads 40) and thecorresponding surfaces of spacer 82 (or test conductor 18). Arrow 86indicates the upward movement of insert 26 and retained DUT 22. Spacer82 provides an upward stop, and the tapered edges of opening 80 serve toshift insert 26 and retained DUT 22 in a horizontal direction as theinsert is being moved upward.

FIG. 5b illustrates upward movement 86 beyond that shown in FIG. 5a.Specifically, pin 70 is being channeled by the sidewall taper of opening80 so that insert 26 is drawn in a horizontal direction as it is pushedupward. Further shown in FIG. 5b is an alternative form of spacer 82.Specifically, spacer 82 may include merely an adjustable length pin (orscrew). Instead of attaching a contiguous layer of rigid material acrossthe underside surface of test socket 16, FIG. 5b illustrates a spacer 82extending from the underneath surface of test socket 16 only within anisolated region of that underneath surface. More particularly, pin 82 isextendable from a small, isolated region of the underside surface oftest socket 16. This allows use of a spacer when the underneath surfaceis substantially congested with, for example, circuit elements ornon-planar surfaces.

FIG. 5c illustrates further upward movement of insert 26 to a stoppingposition. Alternatively, another spacer form is shown, whereby either apin 89 of fixed elongated dimension extends from the underside surfaceof test socket 16, or a contiguous layer of rigid material 82a issecured and therefore extends from the underneath surface. Thecontiguous form can comprise two layers 82a and 82b to form a spacer ofvariable thickness. Alternatively, the pin 89 can include a cap 88placed over an end of pin 89. Layer 82b or cap 88 can be of variablethickness to account for differences in the distance by which insert 26extends upward. Alternatively, layer 82a and pin 86 can be of variablethickness T to account for differences in the extent of verticaldelivery. FIG. 5c further illustrates an alternative lead arrangement,possibly used in a BGA package having an array of solderballs extendingfrom one planar surface of DUT 22 rather than leads extending from theperimeter of DUT 22. Regardless of the lead arrangement and the depth ofeach lead, spacer 82, or adjustable pins with or without caps can beused to account for that variance in depth.

FIG. 6 illustrates a sequence of steps used to self-align leads to testconductors each time a DUT is delivered toward the test socket. Thatalignment occurs in three dimensions using the combination of pins,sockets and spacers proximate to the insert which retains the DUT leadsand the test socket which retains the test conductors.

Initially, a socket card must be produced having the plurality of testconductors 90. An insert can then be produced 92 to a specifiedthickness. The lateral size and configuration of the insert is chosen tomatch the outer footprint or perimeter of the integrated circuit. Theconfiguration of the insert is chosen so that it securely retainsapproximately three sides of the integrated circuit perimeter. A chuckwhich raises and lowers the insert is also machined 94 having a lateralsize and geometry which matches an insert surface opposite the DUT. Asdescribed above, the socket card is produced with preferably two pinsextending downward in registry with an opening formed within the insert.The insert also contains another pair of openings which receive pinsextending from the chuck. Thus, steps 96 and 98 illustrate the pin andopening arrangement within the test socket and insert, respectively.

There may be numerous inserts which can be placed within a carousel andconcurrently heated or cooled. Each insert can retain a correspondingDUT or integrated circuit. Accordingly, a kit can be provided comprisinga plurality of inserts, the socket card and the chuck unique for the DUT100. Once the kit is selected for a particular pin arrangement and/orpackage size, the DUT is placed within an insert 102. The chuck is thenraised against the insert to begin extending the DUT toward the testsocket 104. As the insert approaches the test socket, openings withinthe insert extend over pins protruding from the test socket. The amountby which the insert is driven toward the test socket terminates when theinsert abuts against the spacer 108. Of course, the spacer thickness canvary depending on the amount of compression desired between the DUTleads and corresponding test conductors.

It will be appreciated to those skilled in the art having the benefit ofthis disclosure that this invention is believed applicable to any devicewhich mates relatively small, fine-pitch elements. According to oneembodiment, those elements entail test conductors of an automated testdevice and leads of an integrated circuit. It is understood that theform of the invention show is to be taken as exemplary, presentlypreferred embodiments. Regardless of how the DUT is presented, or theorientation of the DUT to the test head, the present invention is suitedfor ensuring the leads and test conductors are properly aligned witheach other in two dimensions or in three dimensions. The combination ofhardware elements placed proximate to the DUT and test socket as well asthe orientation of the pick-and-place handler to the test head ensuresalignment is rapidly and repeatedly achieved. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense as to possibly numerous variations which fallwithin the spirit and scope of the present invention.

What is claimed is:
 1. An apparatus for aligning an integrated circuitto a test socket, comprising:a test socket adapted to be removablycoupled to a test head, the test socket including a test socket pin; andan insert adapted to be removably coupled to a handler, the insertfurther being adapted to securely retain an integrated circuit as theintegrated circuit is moved by the handler toward the test socket suchthat a pin opening within the insert is brought in mating alignment withthe test socket pin.
 2. The apparatus as recited in claim 1, wherein thetest socket comprises a plurality of test conductors electricallycoupled to a test head.
 3. The apparatus as recited in claim 2, whereinthe integrated circuit comprises a plurality of leads brought intoalignment with the plurality of test conductors during times when thetest socket pin is mated within the opening.
 4. The apparatus as recitedin claim 2, wherein the plurality of test conductors are configured toreceive test signals derived from a test device electrically coupled tothe test head.
 5. The apparatus as recited in claim 1, wherein theinsert comprises a planar element having an insert opening extendingalong a plane formed by the upper surface of the planar element, andprotrusions extending from the plane about the insert opening forfixedly receiving the integrated circuit within the insert openingbetween the protrusions.
 6. The apparatus as recited in claim 5, whereinthe insert opening extends through the planar element along an axisperpendicular to the plane.
 7. The apparatus as recited in claim 6,wherein the protrusions comprise opposed planar surfaces, and whereinthe insert opening is tapered such that a diameter of the insert openingproximate to one of the opposed planar surfaces is greater than adiameter of the insert opening between the opposed planar surfaces. 8.The apparatus as recited in claim 1, wherein the insert comprises aretaining opening on an opposite surface of the insert from the pinopening, wherein the retaining opening is configured to receive a pinextending from a portion of the handler for removably coupling theinsert to the handler.
 9. A kit for aligning a lead of an integratedcircuit to a test conductor of a test socket, comprising:a test socketadapted to be removably coupled to a test head, the test socket having atest socket surface comprising a test socket pin and a test conductorextending from the test socket surface a first spaced distance from eachother; and an insert adapted to be removably coupled to a handler, theinsert comprising an insert surface configured to receive the integratedcircuit, wherein the insert surface comprises a pin opening spaced fromthe lead by a second spaced distance when the integrated circuit isreceived by the insert, and wherein the first spaced distance is equalto the second spaced distance.
 10. The kit as recited in claim 9,wherein the pin opening is dimensioned to receive the test socket pinconcurrent with the test conductor contacting the lead.
 11. The kit asrecited in claim 9, wherein the test socket surface faces the insertsurface.
 12. The kit as recited in claim 9, wherein the test conductoris configured to receive test signals derived from a test deviceelectrically coupled to the test socket.
 13. The kit as recited in claim9, wherein said test socket further comprises another test socket pinand another test conductor extending a third spaced distance from eachother, and wherein said insert further comprises another pin openingspaced from another lead of the integrated circuit by a fourth spaceddistance when the integrated circuit is received by the insert.
 14. Thekit as recited in claim 13, wherein the third spaced distance is equalto the fourth spaced distance.
 15. The kit as recited in claim 13,wherein a distance between said test socket pin and said another testsocket pin is equal to a distance between said pin opening and saidanother pin opening.
 16. The kit as recited in claim 9, furthercomprising a chuck configured to receive a surface of the insertopposite the insert surface and drive the insert surface toward the testsocket surface, and wherein said insert is configured to be removablycoupled to said chuck.
 17. A method for aligning a lead of an integratedcircuit to a test conductor of a test socket, the methodcomprising:inserting the integrated circuit into an insert adapted to beremovably coupled to a handler; moving the insert toward the testsocket, wherein the test socket is adapted to be removably coupled to atest head; and continuing to move the insert toward the test socketwhile laterally shifting the insert relative to, and along a planeparallel to, the test socket when bringing the lead in alignment withthe test conductor.
 18. The method as recited in claim 17, wherein saidmoving comprises pushing a surface of the insert opposite the insertedintegrated circuit with a chuck configured to laterally secure theinsert.
 19. The method as recited in claim 17, wherein said shifting theinsert comprises inserting a test socket pin extending from the testsocket into a pin opening configured within the insert.